The present invention relates to the art of can beading apparatus and, more particularly, to apparatus for beading the wall of a seamless cup-shaped metal can body.
It is of course well known in the can making art to produce a metal can by forming an open ended tubular body and applying an end closure to each end by a flanging and beading process. It is likewise well known that the can body can be provided with a group of peripheral beads intermediate the opposite ends thereof prior to the application of the end closures thereto. When such a can is completed, the flanged and beaded seams between the can body and end closures provide rigidity for the ends of the can and the intermediate body beads provide rigidity for the can intermediate the ends thereof.
It is also well known to produce a two-piece can which includes a one-piece cup-shaped body closed at the open end by a separate end closure applied thereto in the manner employed in connection with the making of three-piece cans. Such a one-piece can body is made by drawing and ironing a cup-shaped blank to a desired axial length, and then trimming the open end so that the can bodies are the same height or axial length. During the ironing and drawing procedure, the end wall of the can body is generally domed or otherwise contoured to rigidify the end wall, and the end wall and side wall blend together about a radiused line of juncture. While the latter structure is sufficient for many uses for the can body, it will be appreciated that such a radiused line of juncture does not provide the rigidity at the corresponding end of the completed can that is achieved by the application of a separate end closure at the open end of the can body. Moreover, the side walls of such one-piece can bodies are extremely thin and, in the absence of care, can be easily dented, creased and/or crushed during handling, either before or after completion of a two-piece can using the same. These characteristics not only lead to production losses as a result of damage or distortion rendering the can body unacceptable before completing the can assembly, but also impose limitations on use and handling of the completed can which detracts therefrom as a commercially acceptable packaging unit.
Accordingly, it becomes desirable to provide peripheral beads in the side wall of a one-piece can body close to the closed end thereof and between the open and closed ends to improve the rigidity in the side wall area adjacent the closed end and to rigidify the side wall so that the overall rigidity of a two-piece can made therewith is improved. Such rigidity advantageously enables handling of the can body during production of the two-piece can, and handling the completed can such as by store merchants or customers, with reduced likelihood of damage to the can body or completed can, thus reducing production losses for the can manufacturer and merchandise losses in the market place. Further, such improved rigidity promotes versatility for two-piece cans with respect to products packaged therein, and promotes acceptability with respect to merchandising arrangements which require stacking of individual cans to considerable heights.